Having escaped the web of the Spider-Man franchise, Marc Webb returns to (500) Days of Summer-sized moviemaking with this soft-focus indie, combining the maths genius elements of Good Will Hunting with the child custody torture of What Maisie Knew. It’s not as smart or original as the former, nor as grotesque as the latter, instead falling into a crevice of mediocrity somewhere between.

Mary (Mckenna Grace) is a precocious, “one-in-a-billion” 7-year-old who, following the death of her mother, lives in her uncle’s ramshackle home. Frank (Chris Evans) left his career as a professor to live a regular-type life as a mechanic. Previously home-schooled, it’s now time for Mary to mix with other kids and make some friends. So, Frank enrols her at a normal school. After she batters a fellow pupil, Mary’s genius comes to attention of the head-teacher. She wants to send Mary to a “gifted” school, but Frank doesn’t want her being exposed to the sort of pressure that pushed his sister – Mary’s mother, Diane – to suicide. Suddenly, Frank’s mother, Evelyn (Lindsay Duncan) literally shows up on their doorstep. She can’t persuade Frank to unleash Mary’s potential, so she takes the issue to court. An ugly battle ensues – not so much over the physical custody of Mary, but custody of her mind. Frank is stuck. Should he allow Mary to flourish, most likely away from him? Or keep her close and safe, yet curtail her actualisation?

From this synopsis, and as the gentle acoustic guitar twangs over the credits, we know what territory we’re in. Within minutes Cat Stevens is crooning on the soundtrack, as Frank and Mary enjoy their idyllic rustic existence, taking joyrides in other people’s boats and trespassing in nice fields.

The most problematic aspect of Gifted relates to the moral quandary at its heart: What to do with Mary. Here we have an underlying appeal to the American right in 2017. She’s a gifted little so-and-so, and when she’s offered scholarly promotion in response to assaulting another child, Frank is scared of Mary becoming a “congressman”, implying an inherent distrust of politicians. He says he wants to “dumb her down into a decent human being.”

This is the film’s slightly sinister and certainly simplistic anti-intellectualist agenda. The espousing of common decency is one thing; asserting a direct equivalence between intellect and moral bankruptcy/psychological destruction is pure Trumpthink. At one point Mary receives a Macbook, which becomes a totem of psychic destruction. A horrified Frank snatches it away for fear that Mary’s mind could be a little too opened. In a further reflection of the state of the country, the film betrays a remarkable acceptance of the litigious culture of the US, with Frank and Evelyn reaching the height of their breezy smugness as they fight over the child’s future. Neither seems in the slightest bit interested in the judge’s reasonable offer to let them sort it out in the corridor.

More successful than the crass custody conflict is the family drama triangle between Frank, Evelyn, and the late Diane. This is the most dramatically arresting area of the movie, and a welcome break from the saccharine predictability of the dishy dad and delightful daughter story. As Evelyn, it’s a moving performance from Lindsay Duncan, who shifts through various degrees of ice-cold before her inevitable thaw. Evelyn is resentful of having had children in the first place; for family having halted her career. Diane, her genius daughter, was to be the continuation of Evelyn’s boundless ambition. But following Diane’s death, Frank is preventing the final catharsis from taking place via Mary.

Of course, to have put Evelyn front-and-centre might have been a hard sell for the moviemakers. Much more palatable to focus on the Regular Joe.

Frank is basically Captain America in overalls. He’s a hunky dad with a manly job and a heart of gold. Evans’ range has the breadth of a city sidewalk; and while he and Grace clearly combine well, I found her performance aggravatingly affected and skin-crawlingly cutesy. She’s a child acting like adults wished children behaved: playful yet soulful; energetic yet patient. Belief can only be suspended so far. The role of Bonnie (Jenny Slate), Mary’s teacher, exists purely to dote on Mary and gaze sympathetically at Frank. Finally, we have Oscar-winner Octavia Spencer in the risibly thankless role of the African-American guiding angel, who comes out with a torrent of sage advice which nobody listens to.

There are some good individual scenes. Mary’s meeting with the court counsellor is a depressingly convincing depiction of how social guardians, with their ears attuned to alarm bells, will hear them everywhere. And there’s a great confrontation at the end, where Frank gets to deliver his withering final blow upon Evelyn. It’s almost worth it for the gasps that greet this scene.

But as a whole, the movie never satisfactorily coalesces. It is pure M.O.R cheese with a creepy ultra-conservative edge, and hasn’t even the mechanical quality of an efficient tearjerker. More toe-curling than heart-rending, it’s one for the bottom of the watchlist when it comes to the small screen.